Missing pregnant teacher, Laura Wallen, of Olney, who had been reported missing last Tuesday, has been found deceased, according to the Montgomery County Police Department.

Wallen's body was discovered in a shallow grave on Prices Distillery Road in Damascus on Wednesday afternoon.

A suspect, later identified as Wallen's boyfriend Tyler Tessier, was arrested in connection to her murder at around 5:30 p.m., police say.

On Thursday, Montgomery County Police Chief Tom Manger told HLN during an interview with Ashleigh Banfield on PrimeTime Justice that Wallen was "shot in the back of the head" following an autopsy conducted by the Medical Examiner's Office in Baltimore.

Murder suspect spoke about missing girlfriend on Monday

On Monday, Tessier spoke at a press conference with Wallen's family claiming that "all he cared about was that she come back," according to ABC7's Tom Roussey.

Police say Tessier's presence at that press conference was "calculated."

According to authorities, Tessier may have had at least two other girlfriends while dating Wallen.

Watch the press conference in full below:

Vigil held in memory of murdered teacher

In a parking lot across the street from Wilde Lake High School, where Wallen was named Teacher of the Year in 2016, students, parents, and school employees gathered Wednesday night to comfort each other and mourn Wallen’s death.

They had planned an event called a “gathering of hope” for Wallen’s safe return. But the sad news began hitting the Wilde Lake High community a little over an hour before the event was scheduled to start.

“She influenced us to be better in life. Not just in school – in life,” said Hamad Wasti, who graduated from Wilde Lake this past spring.

He and two friends said Wallen is the reason they were able to graduate high school.

“She just turned it around,” Jawan Taylor said of his time at Wilde Lake. “She made sure that I did what I had to do. As a student, as a person, as a man.”

While the students were together in Columbia, in Gaithersburg, Montgomery County Police were announcing Wallen’s boyfriend had been arrested. The news gave students another shock on what had already been a very tough night.

“How could you be possessed with so much hate to take a soul that means so much to people?” said an emotional Saquan Maxwell, who says Wallen was his mentor.